Speaking at a launch of Charles Moore’s biography about Margaret Thatcher, he said: “The best thing possible for the education of the denizens of the heaving hemp-smelling bivouacs that now litter Trafalgar Square and Hyde Park would be for them to stop blocking the traffic and buy a copy of Charles’s magnificent book so that they can learn about a true feminist, green and revolutionary who changed the world for the better.”

Mr Johnson said he had been advised by his security staff not to attend last night’s book launch “because they said the road was full of uncooperative crusties and protesters of all kinds littering the road”.

Extinction Rebellion demonstrators sit with their tents at Whitehall in London earlier this week. Picture: Peter Summers/GettySource:Getty Images

The Met Police arrested 319 activists in one day — far more than the 122 figure of arrests made during the first day of the April protests.

Among the activists in Trafalgar Square were celebrities including model Daisy Lowe, comedian Ruby Wax and actors Juliet Stevenson and Mark Rylance.

“The collapse of society is certain,” Rylance said in a speech to the crowd.

Specialist officers cut some of the protesters out of a car parked outside the Ministry of Defence.

Two women were married on Westminster Bridge at a ceremony watched by about 100 protesters, who sang hymns and said a prayer.

But not everyone was pleased with the day of action — with some arguing the UK was cutting carbon emissions faster than any other G7 nation.

Over the next fortnight, protesters will also target London City Airport, which they will attempt to hold for three days.

Those behind the protest admitted their action could have an impact on St Thomas’s hospital, which sits on the opposite bank of the Thames from the Houses of Parliament.

When asked whether they were worried about disruption at the hospital, activist Savannah Lovelock said they were “really sorry … but we are running out of time”.

Activists protest in London on October 8. Picture: Ben Stansall/AFPSource:AFP

This article originally appeared on The Sun and has been republished with permission